Identifier
Values
[1] => 0
[2] => 0
[1,1] => 1
[3] => 0
[2,1] => 1
[1,1,1] => 0
[4] => 0
[3,1] => 1
[2,2] => 1
[2,1,1] => 1
[1,1,1,1] => 1
[5] => 0
[4,1] => 1
[3,2] => 2
[3,1,1] => 2
[2,2,1] => 2
[2,1,1,1] => 2
[1,1,1,1,1] => 0
[6] => 0
[5,1] => 1
[4,2] => 3
[4,1,1] => 3
[3,3] => 2
[3,2,1] => 6
[3,1,1,1] => 4
[2,2,2] => 2
[2,2,1,1] => 4
[2,1,1,1,1] => 2
[1,1,1,1,1,1] => 1
[7] => 0
[6,1] => 1
[5,2] => 4
[5,1,1] => 4
[4,3] => 5
[4,2,1] => 12
[4,1,1,1] => 7
[3,3,1] => 8
[3,2,2] => 8
[3,2,1,1] => 14
[3,1,1,1,1] => 6
[2,2,2,1] => 6
[2,2,1,1,1] => 6
[2,1,1,1,1,1] => 3
[1,1,1,1,1,1,1] => 0
[8] => 0
[7,1] => 1
[6,2] => 5
[6,1,1] => 5
[5,3] => 9
[5,2,1] => 20
[5,1,1,1] => 11
[4,4] => 5
[4,3,1] => 25
[4,2,2] => 20
[4,2,1,1] => 33
[4,1,1,1,1] => 13
[3,3,2] => 16
[3,3,1,1] => 22
[3,2,2,1] => 28
[3,2,1,1,1] => 26
[3,1,1,1,1,1] => 9
[2,2,2,2] => 6
[2,2,2,1,1] => 12
[2,2,1,1,1,1] => 9
[2,1,1,1,1,1,1] => 3
[1,1,1,1,1,1,1,1] => 1
[9] => 0
[8,1] => 1
[7,2] => 6
[7,1,1] => 6
[6,3] => 14
[6,2,1] => 30
[6,1,1,1] => 16
[5,4] => 14
[5,3,1] => 54
[5,2,2] => 40
[5,2,1,1] => 64
[5,1,1,1,1] => 24
[4,4,1] => 30
[4,3,2] => 61
[4,3,1,1] => 80
[4,2,2,1] => 81
[4,2,1,1,1] => 72
[4,1,1,1,1,1] => 22
[3,3,3] => 16
[3,3,2,1] => 66
[3,3,1,1,1] => 48
[3,2,2,2] => 34
[3,2,2,1,1] => 66
[3,2,1,1,1,1] => 44
[3,1,1,1,1,1,1] => 12
[2,2,2,2,1] => 18
[2,2,2,1,1,1] => 21
[2,2,1,1,1,1,1] => 12
[2,1,1,1,1,1,1,1] => 4
[1,1,1,1,1,1,1,1,1] => 0
[10] => 0
[9,1] => 1
[8,2] => 7
[8,1,1] => 7
[7,3] => 20
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Description
The number of standard desarrangement tableaux of shape equal to the given partition.
A standard desarrangement tableau is a standard tableau whose first ascent is even. Here, an ascent of a standard tableau is an entry $i$ such that $i+1$ appears to the right or above $i$ in the tableau (with respect to English tableau notation).
This is also the nullity of the random-to-random operator (and the random-to-top) operator acting on the simple module of the symmetric group indexed by the given partition. See also:
A standard desarrangement tableau is a standard tableau whose first ascent is even. Here, an ascent of a standard tableau is an entry $i$ such that $i+1$ appears to the right or above $i$ in the tableau (with respect to English tableau notation).
This is also the nullity of the random-to-random operator (and the random-to-top) operator acting on the simple module of the symmetric group indexed by the given partition. See also:
- St000046The largest eigenvalue of the random to random operator acting on the simple module corresponding to the given partition.: The largest eigenvalue of the random to random operator acting on the simple module corresponding to the given partition
- St000500Eigenvalues of the random-to-random operator acting on the regular representation.: Eigenvalues of the random-to-random operator acting on the regular representation.
Code
def tableau_ascents(t):
r"""
The (sorted list) of ascents of the standard tableau `t`.
An *ascent* of a standard tableau `t` is an entry `i`
such that `i+1` apears to the right or above `i` in `t`
(in English notation for tableaux).
"""
locations = {}
for (i, row) in enumerate(t):
for (j, entry) in enumerate(row):
locations[entry] = (i, j)
ascents = [t.size()]
for i in range(1, t.size()):
# ascent means i+1 appears to the right or above
x, _ = locations[i]
u, _ = locations[i+1]
if u <= x:
ascents.append(i)
return sorted(ascents)
def is_desarrangement_tableau(t):
r"""
Test whether a tableau is a desarrangement tableau.
A *desarrangement tableau* is a standard tableau
whose first ascent is even.
"""
return min(tableau_ascents(Tableau(t))) % 2 == 0
def statistic(la):
return len([t for t in StandardTableaux(la) if is_desarrangement_tableau(t)])
Created
May 24, 2016 at 23:10 by Franco Saliola
Updated
Jun 11, 2016 at 01:03 by Martin Rubey
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